Solid fuel burner



Dec.4,1934. E l -MER AN 1,983,059

501511) FUEL BURNER Filed March 50, 1932 IN VEN TOR Egyz'l Z immerman Patented Dec. 4, 1934 rasaosa UNITED STATES PATENT oFF -cs some FUEL BURNER Emil Zimmerman, Everett, Wash, Application March so, 1932, Serial No. 602,009

1 Claim. (01. 122-30 My invention relates to burners, more particularly toburners using solid fuel such as coal or other solid fuel of granular character, for use in connection with any heating plant such as hot 5' air, hot water, or steam.

It is customary with burners of this type to feed the fuel into the combustion chamber through a hopper positioned above and indirect communication with the combustion chamber. Because of this location of the combustion chamber the hopper and the fuel therein become hot, the fuel in the hopper being heated to the point where distillation takes place. As the heat increases,

a the fuel in the hopper smokes and gas forms li within the hopper, causing smoke and fumes to be diffused throughout the house. Various means have been proposed for removing such smoke and fumes, but so far as I am aware, it has not been proposed heretofore to prevent their formation. The main object of my invention is to prevent production of such smoke and fumes. More specifically it is an object to accomplish this end by keeping the burner cool, particularly above the combustion chamber, so that the fuel thereabove m is maintained below the point of distillation.

A further object is to provide a burner which is simple but sturdy in construction, one which can be easily installed upon any furnace, and one ,which is easily accessible for cleaning.

These and other objects will be best ascertained from a study of the accompanying drawing and of the specification and claim.

In the accompanying drawing I have. shown my ,invention in a form which is at present preferred by me, and have so described it in the present specification, whereof the claim particularly points out that which I believe to be my invention.

Figure 1 is a front elevation of my burner in 1 operative position relative to a furnace.

Figure 2 is a vertical central sectional view of the same.

An upstanding chute 1 is conveniently formed with a combustion chamber 10 at its bottom. The

combustion chamber and the chute are preferably *of slight thickness from front to rear, for a reason which will appear hereafter. A combustion outlet 12 is provided in the side of the chute, above the bottom. This outlet is inclined upwardly to pro- .ject into a suitable opening in a furnace F. As the furnace forms no part of my invention I have only shown a simple representativeform of furnace having an outlet flue O. A clean-out opening 17 may be provided opposite the combustion .outlet in the front of the chute, this being normally closed by a double door 18.

The chute may be flared somewhat to facilitatefeeding of the fuel. To this end the rear side 13 of the chute may be inclined slightly, providing a wider opening at the bottom than at the top. It will be noticed that the bottom edge of the rear wall 13 is not directly over the rear wall of the combustion chamber but considerably closer to the front'of the chute. With such a construction the fuel feeding down from the rear side of the hopper does not enter the combustion outlet.

Any suitable form of grates may be used to enclose the bottom of the combustion chamber. Preferably, however, I employ two types of grates, one of which, 14, is operated manually, the other of which, 15, may be continuously rotated by any suitable power means through the drive gear 16.

In order to keep the combustion chamber, the chute, and the fuel in the latter cool, a suitable water jacket 2, integral with the chute, surrounds the chute l and encloses it, or at least lies against the slightly spaced front and rear walls. Water may be supplied to the jacket from any source. In my present form, however, it may be considered that the furnace is a hot water furnace, and connections are shown from the water jacket to the furnace. An inlet pipe 20 connects the bottom of the water jacket to the furnace, and supplies cool water to the jacket, while an outlet pipe 21 connects the top of the jacket to the top of the furnace hot water system, and water heated in the jacket is led oil. to the boiler.

Because the chute is not thick, the temperature of the chute walls will affect the temperature of the fuel contained within the chute. Thus the fuel is kept cool by indirect application of a cooling medium, namely, by reason of water circulating through the jacket, adjacent the chute. Since this water is kept at a temperature below the point of distillation of the fuel no gases can emerge from the chute 1. Accordingly the fuel is kept cool, and is in fact maintained cool until it approaches very close to the combustion zone. Furthermore, any draft out the outlet pipe 12 which cannot be satisfied by air entering from beneath the grate is supplied by air entering at 43 past a nearly balanced auxiliary draft door 42 so mounted as automatically to swing open enough under the influence of reduced pressure to admit auxiliary air, and thence through holes 41 in the adjacent wall of the fuel space. This cool air, drawn down through the fuel in the chute, additionally cools it, and supplies the additional air needed for perfect combustion.

Since the fuel is only permitted to distill or ignite when in the combustion zone, and since in the combustion zone sufiicient air is supplied to support complete combustion, the fuel burns without the production of smoke, and the burner may be said to be smokeless. Being smokeless, soot cannot collect in flues and chimneys, with the incident danger and expense for cleaning.

The chute, if not supported on the floor, is conveniently supported by a casing 3, open at its top to receive ashes passing through the grates. A door 30, pivoted at the bottom of the ash pit, normally closes the pit. In order to supply a draft to the combustion chamber a draft door 31 would be provided below the grates, in the casing 3.

The chute, above the combustion chamber, holds sufiicient fuel to feed the combustion chamber for some time, but where an additional supply is required I provide a hopper 4 removably secured to the top of the chute in any suitable manner. A hinged cover 40 may be provided to normally close the top of the hopper. The auxiliary draft opening 43 may be in the chute itself, or in the hopper, as shown.

What I claim as my invention is:

A burner for solid fuel comprising an upstanding chute terminating at its lower end in a combustion chamber, and having a side outlet for the products of combustion, a grate structure at the bottom of the chute and combustion chamber, a water jacket surrounding the chute and extending downward to include the combustion chamber, means for circulating water therethrough to maintain the fuel above the combustion chamber below distillation temperatures, a draft inlet beneath the grate, an auxiliary air inlet in the upper portion of the chute, and a door swung at the top of said auxiliary air inlet upon a horizontal axis, and weighted to normally swing shut, and swinging open under the influence of reduced pressure in the chute.

EMIL ZIMMERMAN. 

